func (c *Container) acquireLock(name string) (*lockfile.Lockfile, error) {
lock, err := lockfile.New(fmt.Sprintf("/tmp/lxc-%s.lock", name))
if err != nil {
log.Printf("Cannot initialize lock: %s", err)
return nil, err
}
startTime := time.Now()
for {
err = lock.TryLock()
if err != nil {
if time.Since(startTime) > lockTimeout {
return nil, err
}
if err == lockfile.ErrBusy {
log.Printf(`Lock "%v" is busy - retrying in 3 seconds`, lock)
time.Sleep(3 * time.Second)
continue
}
} else {
return lock, nil
}
}
}
func ExampleLockfile() {
lock, err := lockfile.New("/tmp/lock.me.now.lck")
if err != nil {
fmt.Printf("Cannot init lock. reason: %s\n", err)
panic(err)
}
err = lock.TryLock()
// Error handling is essential, as we only try to get the lock.
if err != nil {
fmt.Printf("Cannot lock \"%v\", reason: %s\n", lock, err)
panic(err)
}
defer lock.Unlock()
fmt.Println("Do stuff under lock")
// Output: Do stuff under lock
}
